| This study examined the taxonomy, molecular phylogeny, and taxol production in selected genera of endophytic fungi associated with tropical and temperate plants. These common anamorphic endophytes are Pestalotiopsis, Pestalotia, Monochaetia, Seiridium, and Truncatella, forming appendaged conidia in acervuli. Sexual states of these fungi, including Amphisphaeria, Pestalosphaeria, Discostroma and Lepteutypa , are in a little known family Amphisphaeriaceae, an uncertain order of Xylariales or Amphisphaeriales (Pyrenomycetes, Ascomycota).; The classification of the anamorph is based primarily on conidial morphology i.e. the number of cells, and appendage type. However, UV irradiation can convert typical conidia of Pestalotiopsis microspora (5 celled, 2–3 apical and 1 basal appendage) into fungal biotypes that bear a conidial resemblance to the genera Monochaetia and Truncatella . The single cell cultures of putants retain 100% homologies to 5.8S and ITS regions of DNA in the wild type, suggesting that no UV induced mutation occurred in these regions. These results call to question the stability of conidial morphology and taxonomic reliance on this characteristic for this group of fungi. Therefore, a molecular phylogenetic approach was used to clarify their taxonomic relationships.; Teleomorphs of these endophytes were previously placed in either Xylariales or Amphisphaeriales. Based on parsimony analysis of partial 18S rDNA sequences for selected anamorphic and teleomorphic taxa in Amphisphaeriaceae, this research supports the placement of these fungal genera in the order Xylariales sharing a common ancestor with some taxa in Xylariaceae. The 18S rDNA region is helpful in resolving phylogenetic relationships at or above the ordinal level for these sampled taxa.; Parsimony analyses of the ITSI-5.8S-ITS2 sequences suggest that selected genera in Amphisphaeriaceae are a monophyletic group sharing the synapomorphic characteristic of an anamorphic state which has an annellidic holoblastic type of conidiogenesis in acervuli of textura angularis cells. These taxa were delineated into 5 groups somewhat consistent with previous classical classifications. Many of the taxa in this group of fungi are either closely related or identical according to the 97–100% homologies of the complete ITS1-5.8S-ITS2 regions. Results reflect a correlation between host and the geographical origin for some clades of the inferred tree. A majority of temperate taxa are with gymnosperm hosts, and one group is on tropical palm. Taxol production was detected only in anamorphs, particularly in Seiridium, and for genera on palm or yew, but this may reflect sampling bias. |
